Metal-insulator-metal (MIM) capacitors can be used in various integrated circuits such as analog frequency tuning circuits, switched capacitor circuits, filters, resonators, up-conversion and down-conversion mixers, and A/D converters. A conventional MIM capacitor includes a top metal layer, an insulator layer and a bottom metal layer, in which the top metal layer, the insulator layer and the bottom metal layer are vertically stacked on a semiconductor substrate and occupy quite a large surface area of the semiconductor substrate, and thus the capacitance of the conventional MIM capacitor is restricted by the limited area of the semiconductor substrate, and a device formed thereby will be constrained due to chip design rules. The conventional MIN capacitor requires many masks, and has a complicated manufacturing process.